False twister device

ABSTRACT

A false twister device for textile yarns, particularly for increasing the volume of continuous synthetic yarns, in which the yarn is compelled to follow a zig-zag pattern coming into contact with discs of relatively yieldable material, the discs being rotated by friction by at least one wear resistant cylinder in contact with them.

United States Patent [191 Marzoli Dec. 17, 1974 FALSE TWISTER DEVICE 3,021,663 2/1962 Findlow 57/774 3,2 7, ll l966 M I h [75] Inventor: Angelo Marzoli, Bergamo, Italy 3 41967 3 22: a! I I u 73 Assignee: F. LLI Marzoli & c. S.p.A., 3,705,488 12/1972 Sholly P l o (B escia), Ennneklng t. X

[22] Filed: Oct. 25, 1973 Primary Examiner-Donald Watkms PP 411,354 Attorney, Agent, or Firm-Eric H. Waters [30] Foreign Application Priority Data Oct. 31, 1972 Italy 31186/72 [57] ABSTRwT A false twister device for textile yarns, particularly for increasing the volume of continuous Synthetic yams, I c p e u I n a 6 6 1 e 6 e 1 l I v u I u s n I l n v e 6 u v u a e I v u n a I a [58] Fleld of Search 57/34 tern coming into contact with discs of relatively yieldable material, the discs being rotated by friction by at [56] References cued least one wear resistant cylinder in contact with them.

UNITED STATES PATENTS 2,939,269 6/1960 Dobson 57/77.4 5 Claims, 6 Drawing Figures sum 2 or 3 PATENTEL EEC] 71874 This invention relates to a false twister device for increasing the volume, particularly of continuous filament synthetic yarn originating from a feed spool and collected, after passage through the false twister device, on a second spool or on cops.

False twister devices are known in which the false twist is obtained by placing the synthetic yarn, travelling at a fairly high speed, into contact with the periphery of rotating means. This contact ismade under pres sure and is such that the rotating means transmit their rotating motion to the yarn by friction. As the yarn inn unwound from the feed spool and wound on the collection spool, a false twist is imparted thereto it this manner.

As said rotating means must transmit their motion to the yarn by friction without subjecting it to noticeable wear, the means must consist of material having characteristics such as to generating sufficient friction for transmitting the motion but to keep the wear on the yarn at a minimum. Because of said friction, the rotating means themselves are subjected to wear by the yarn in contact with them.

Usually the rotating means, such as discs or rings, are rotated at a constant angular speed by connection to a constant speed motor, for example by way of toothed gearing. The outer diameter of the disc or the inner diameter of the ring respectively varies according to the extent of wear, and hence reduces or increases the peripheral speed in the zone of contact with the synthetic yarn in an undesirable manner.

In order to keep the yarn in contact with the outer profile of the rotating means, suitable guide means must be disposed upstream and downstream of these latter so as to prevent the yarn from being dragged by the movement of the rotating means.

Up to the present time said guide means have not permitted the reliable and adjustable positioning of the yarn at the rotating means, and because of this the false torsion has not been obtained with the required efficiency and constancy.

From the aforementioned disadvantages it can be seen that in false twisting devices of known type, the problem arises of obtaining a false twist which remains constant or varies only within very small limits, and especially of obtaining a predetermined false twist.

An object of the present invention is to eliminate the aforementioned disadvantages, enabling a false torsion to be obtained which is adjustable at the commencement of working and which remains substantially constant during working.

This object is attained by a false twister device of the type heretofore described, comprising a frame provided with supports carrying discs of relatively yieldable material disposed with their axes parallel with each other and lying in parallel planes to define a zigzag passage for the yarn, rotated by drive means and arranged to come into contact with a yarn traversing the zigzag passage. The discs are rotated by friction by at least one wear resistant cylinder in contact with them.

Advantageously the cylinder is formed of wear resistant material, so that it is more resistant to wear by the rotating disc itself, while the rotating disc consists of material having such characteristics as not to cause wear of the yarn designed to come into contact with it.

The mutual positions of the parallel axes of the discs and of the planes in which they lie are adjustable in order to adjust and optimize the peripheral speed impressed on the yarn.

An open thread guide ring is disposed respectively upstream and downstream of each disc so as to keep the yarn in position at the discs and ensure its efficient contact with the discs.

In order to adjust and regulate said position and said contact, the thread guide rings are carried in an angularly and vertically adjustable position by supports mounted in turn in an adjustable position on the supports of the frame, in particular on the supports carrying the discs.

In order to take up slack caused by wear of the discs, the drive cylinder is preferably kept in contact with the discs by elastic means.

Consequently, the peripheral speed of the drive cylinder, which is negligible in wear, is transmitted to the yarn without variation, even if the rotating disc decreases in diameter because of wear.

One embodiment of the invention is explained in detail hereafter by way of non-limiting example with reference to the figures of the accompanying drawings, wherein FIG. 1 is a general schematic view of a false twister apparatus employing the device according to the invention;

FIG. 2 is a partially sectional schematic elevational view of the device;

FIG. 3 is a view of the device from above;

FIGS. 4 and 5 are elevational and plan views respectively of a detail of the device; and

FIG. 6 shows very schematically a possible disposition assumed by the thread guide rings.

A continuous filament synthetic yarn 2 is unwound from a feed spool l, and, suitably led by a thread guide 3 and guide wheel 4, is fed to a pressure roller 5 driven by a rotating cylinder 6. The yarn 2 is passed subsequently through a heating oven 7 in which it is kept in contact with the heating means by a pressure lever 8 disposed at the exit of the oven 7. After this passage, the yarn 2 runs on a cooling plate 9, which lowers the temperature of the yarn 2, for example to 200 C in order to make it workable in the false twister device 10, from which the yarn 2 passes on a thread guide 11 to a collection spool 12 on which it is wound.

The description given heretofore relates to one possible embodiment of the device according to the invention, inserted between constructional assemblies which are not further explained because they are well known to experts of the art.

The false torsion twister device 10, according to the invention, comprises a base consisting of a plate 13 (in FIG. 2 this is broken at the center) having slots l4, 15. Columns 16 and 17 are fixed on the plate 13 by bolts 18 and 19 which pass through the slots 14 and 15 respectively. A rotatable and displaceable support 21 is fixed on the column 16 by bolts 20 and comprises two arms 22 and 23, and two rotatable and displaceable supports 26 and 27 are fixed on the column 17 by bolts 24 and 2S and comprise arms 28 and 29 respectively.

A freely rotatable disc 30 is mounted below the arm 29, a disc 31 is mounted above the arm 23 and a disc 32 is mounted above the arm 28. The discs 30, 31, 32 are made of relatively yieldable material, preferably an elastomer, of lesser hardness than the the synthetic yarn 2 to be worked. The discs have a rounded profile and their axes are parallel to each other, the discs themselves lying in parallel planes. The disc 31 is interposed between the discs and 32 in such a manner as to create a zig-zag passage.

Supports 34, each comprising a pivot 35 on which a rotatable and displaceable bush 36 is fixed by a screw 37, are fixed by bolts 33 above the arms 22 and 29 and below the arms 23 and 28. Each bush 36 rigidly carries an angular element 38 which in its turn carries an open thread guide ring 39, 40, 41, 42 respectively, said rings being disposed upstream and downstream of each disc in accordance with the arrow 43 indicating direction of yarn travel.

Each support 34, as shown in FIGS. 4 and 5, also has a slot 44 through which the bolt 33 passes, so that the support is displaceable horizontally along the longitudinal axis of the respective support arm.

As clearly visible in FIG. 3, the discs 30, 31, 32 are in contact with a cylinder 45. In order to ensure sufficient pressure between the cylinder 45 and said discs, the arms 22, 28, 29 are provided with holes 46 in which return springs are hooked and are fixed at their other end to a fixed cross member 48. The cylinder 45 is rotated about its axis by a belt 49 driven by means of suitable drive means, not shown in the FIGURE.

From the description of the components of the device according to the invention the operation is as follows.

The cylinder 45 is rotated at the required speed and because of the pressure existing between the cylinder 45 and the discs 30, 31, 32 it transmits its rotary motion by friction to said discs, which rotate in the same direction of rotation. The yarn 2 enters with a determined linear speed in the device, guided by the ring 39, and comes into contact with the disc 30 which imparts a given peripheral speed to it by friction. Having passed the disc 30, the yarn 2 guided by the ring passes into contact with the second disc 31, after which it is guided by the ring 41 to come finally into contact with the disc 32 from which it is withdrawn by the ring 42 as it leaves the device 10. I

The mutual position of the discs 30, 31, 32 can be varied within certain limits, both vertically and horizontally, in order to adjust and optimize the peripheral speed of the yarn 2 and hence its false twist. Vertically said mutual position is varied by changing the distances between the planes which the discs 30, 31, 32 lie, and this is done by moving the supports 26 and 27 along the column 17 by acting on the bolts 24 and 25, or by moving the support 21 along the column 16.

Horizontal adjustment is made either by rotating the support 21 about the column 16 and/or the supports 26 and 27 about the column 17, or by moving the columns 16 and 17 along the plate 13 by acting on the bolts 18 and 19.

The position of the thread guide rings 39, 40, 41, 42 can be varied with respect to the discs 30, 31, 32, namely along the longitudinal axes of the arms 22, 23, 28, 29 by moving the respective supports 34 by slackening the bolts 33 in the slots 44, and/or in the vertical direction by moving the bushes 36 along the pivots 35 by slackening the bolts 36 and/or by rotation in the horizontal plane about the pivots 35. FIG. 6 shows schematically one of the possible positions assumed by the thread guide rings.

If, after the device has operated for a certain time the discs 30, 31, 32 become worn and their outer diameter is reduced, the springs 47 keep saiddiscs in continual contact with the cylinder 45 by exerting a force greater than fixing force of the bolts 20, 24, 25 on the arms 22, 28, 29, and hence there is an automatic takeup of the slack caused by wear.

As the cylinder 45 is constructed of relatively strong and wear resistant material, its peripheral speed V, is practically constant with time. Moreover, the transmission of the rotary motion takes place without appreciable slip because of the high friction between the cylinder 45, the discs 30, 31, 32 and the yarn 2, and it can be presumed that the peripheral speed V of the discs 30, 31, 32 and the speed V of the yarn 2 are equal to each other and to V i.e., V, V V

If the diameter of the yarn 2 is constant and does not undergo variation, its angular speed about its own axis and hence the degree of false twist also remains constant independent of wear phenomena of the discs 30, 31 and 32. In fact any reduction in their diameter caused by wear is compensated by their greater angular speed.

In conclusion, it should be noted that a roller more wearable than the yarn itself must come into contact with the synthetic yarn so as not to subject it to wear. Thus, in order to compensate for the reduction in diameter of the roller due to the inevitable wear, its angular speed is increased to keep its peripheral speed constant, this being attained by a drive cylinder of neglibible wear.

What I claim is:

l. A false twister device for increasing the volume of textile yarn, and particularly continuous filament synthetic yarn, said device comprising a frame including supports, discs of relatively yieldable material mounted on said supports and having axes parallel with each other and lyingin parallel planes to define a zig-zag passage for the yarn, drive means for rotating said discs which come into contact with the yarn traversing the zig-zag passage, said drive means including at least one wear resistant cylinder in contact with said discs to rotate the same by friction therebetween and means for adjusting the distances between the parallel axes of the discs and between the planes in which they lie.

2. A false twister device for increasing the volume of textile yarn, and particularly continuous filament synthetic yarn, said device comprising a frame including supports, discs of relatively yieldable material mounted on said supports and having axes parallel with each other and lying in parallel planes to define a zig-zag passage for the yarn, drive means for rotating said discs which come into contact with yarn traversing the zig zag passage, said drive means including at least one wear resistant cylinder in contact with said discs to rotate the same by friction therewith, and a thread guide mounted on said frame and disposed respectively upstream and downstream of each disc.

3. A device as claimed in claim 2 comprising means mounting each thread guide in an angularly and vertically adjustable position on said frame.

4. A device as claimed in claim 3, in which said mounting comprises a support member mounted in a horizontally adjustable manner on a respective one of said supports of the frame.

which come into contact with yarn traversing the zigzag passage, said drive means including at least one wear resistant cylinder in contact with said discs to rotate the same friction therebetween and elastic means urging the discs in contact with said cylinder. 

1. A false twister device for increasing the volume of textile yarn, and particularly continuous filament synthetic yarn, said device comprising a frame including supports, discs of relatively yieldable material mounted on said supports and having axes parallel with each other and lying in parallel planes to define a zig-zag passage for the yarn, drive means for rotating said discs which come into contact with the yarn traversing the zig-zag passage, said drive means including at least one wear resistant cylinder in contact with said discs to rotate the same by friction therebetween and means for adjusting the distances between the parallel axes of the discs and between the planes in which they lie.
 2. A false twister device for increasing the volume of textile yarn, and particularly continuous filament synthetic yarn, said device comprising a frame including supports, discs of relatively yieldable material mounted on said supports and having axes parallel with each other and lying in parallel planes to define a zig-zag passage for the yarn, drive means for rotating said discs which come into contact with yarn traversing the zig-zag passage, said drive means including at least one wear resistant cylinder in contact with said discs to rotate the same by friction therewith, and a thread guide mounted on said frame and disposed respectively upstream and downstream of each disc.
 3. A device as claimed in claim 2 comprising means mounting each thread guide in an angularly and vertically adjustable position on said frame.
 4. A device as claimed in claim 3, in which said mounting comprises a support member mounted in a horizontally adjustable manner on a respective one of said supports of the frame.
 5. A false twister device for increasing the volume of textile yarn, and particularly continuous filament synthetic yarn, said device comprising a frame including supports, discs of relatively yieldable material mounted on saud supports and having axes parallel with each other and lying in parallel planes to define a zig-zag passage for the yarn, drive means for rotating said discs which come into contact with yarn traversing the zig-zag passage, said drive means including at least one wear resistant cylinder in contact with said discs to rotate the same friction therebetween and elastic means urging the discs in contact with said cylinder. 